Cushioned rubber floor mat article comprising at least one integrated rubber protrusion and at least two layers of rubber

Abstract

This invention relates to a cushioned dust control mat article wherein the mat comprises at least two distinct layers of rubber, one comprising foam rubber, the other comprising solid rubber. The solid rubber layer is present over the foam rubber layer on the side of the mat in which at least one integrated rubber protrusion is present to provide cushioning characteristics. The solid rubber layer acts as a cap or barrier for the foam rubber layer, particularly over the integrated protrusion or protrusions, in order to provide a mat which is resilient, will not easily degrade in its modulus strength after appreciable use and/or washing within industrial cleaning processes, and will not exhibit appreciable cracking or breaking, particularly within the integrated protrusion(s), after standard use for pedestrian traffic. A method of producing such an inventive cushioned floor mat article is also provided.

We claim:  
     
       1. A cushioned rubber floor mat capable of withstanding rigorous industrial machine washing procedures comprising 
       a rubber mat structure comprising  
       at least a first layer comprised of foam rubber; and  
       at least a second layer comprised of solid rubber having a thickness of between about 2 to about 50 mils, wherein said rubber is selected from NBR, SBR, carboxylated NBR, carboxylated SBR, chlorinated rubber, silicon-containing rubber, EPDM, and any mixtures thereof;  
       wherein at least one protrusion integrated within said rubber mat structure is present having a core portion and an outside surface portion, wherein the core portion of said at least one protrusion is comprised of said first layer of foam rubber, wherein the outside surface portion of said at least one protrusion is comprised of said second layer of solid rubber.  
     
     
       2. The floor mat of  claim 1  wherein said at least one protrusion integrated within said mat structure is substantially cylindrical in shape. 
     
     
       3. The floor mat of  claim 1  where a plurality of protrusions integrated within said rubber mat structure is present. 
     
     
       4. The floor mat of  claim 1  wherein the thickness of the resultant first layer of foam rubber is from about 5 to about 500 mils and wherein said foam rubber is selected from NBR, SBR, carboxylated NBR, carboxylated SBR, chlorinated rubber, silicon-containing rubber, EPDM, and any mixtures thereof. 
     
     
       5. The floor mat of  claim 4  wherein the thickness of the resultant first layer of foam rubber is from about 25 to about 400 mils and the thickness of the resultant second layer of solid rubber is from about 4 to about 40 mils. 
     
     
       6. The floor mat of  claim 5  wherein the thickness of the resultant first layer of foam rubber is from about 40 to about 250 mils and the thickness of the resultant second layer of solid rubber is from about 5 to about 35 mils. 
     
     
       7. The floor mat of  claim 6  wherein the thickness of the resultant first layer of foam rubber is from about 75 to about 200 mils and the thickness of the resultant second layer of solid rubber is from about 5 to about 25 mils. 
     
     
       8. A method of forming a cushioned dust control mat comprising the steps of 
       (a) laying at least a first layer of unvulcanized solid rubber over at least a portion of at least a second layer of unvulcanized rubber further comprising at least one blowing agent to form a closed-cell foam rubber structure upon vulcanization, wherein said second layer of unvulcanized rubber has a thickness of from about 2 to about 50 mils and comprises rubber selected from the group consisting of NBR, SBR, carboxylated NBR, carboxylated SBR, chlorinated rubber, silicon-containing rubber, EPDM, and any mixtures thereof;  
       (b) placing a die having at least a first and second side over at least a portion of said first layer of unvulcanized solid rubber, wherein said die has at least one portion thereof removed to allow for the entry of molten rubber, and wherein said die is comprised of a material which can withstand vulcanization temperatures and pressures; and  
       (c) subjecting the resultant composite comprising the first and second layers of unvulcanized rubber and the die to vulcanization temperatures and pressures to (1) attach the first layer of rubber to said second layer of rubber, and (2) to form at least one rubber protrusion through the removed portions of the die, wherein said resultant rubber protrusion comprises a core of foam rubber and an outside surface of solid rubber; wherein said the thickness of said second layer of rubber is from about 2 to about 50 mils.  
     
     
       9. The method of  claim 8  wherein the thickness of the resultant first layer of foam rubber is from about 5 to about 500 mils and wherein said foam rubber is selected from NBR, SBR, carboxylated NBR, carboxylated SBR, chlorinated rubber, silicon-containing rubber, EPDM, and any mixtures thereof. 
     
     
       10. The method of  claim 9  wherein the thickness of the resultant first layer of foam rubber is from about 25 to about 400 mils and the thickness of the resultant second layer of solid rubber is from about 4 to about 40 mils. 
     
     
       11. The method of  claim 10  wherein the thickness of the resultant first layer of foam rubber is from about 40 to about 250 mils and the thickness of the resultant second layer of solid rubber is from about 5 to about 35 mils. 
     
     
       12. The method of  claim 11  wherein the thickness of the resultant first layer of foam rubber is from about 75 to about 200 mils and the thickness of the resultant second layer of solid rubber is from about 5 to about 25 mils. 
     
     
       13. The method of  claim 8  wherein the removed portions of said die of step “b” permit contact of said molten rubber with both said first side and said second side of said die. 
     
     
       14. The method of  claim 13  wherein said removed portions of said die are substantially circular in shape on the surface of both of said first and second sides of said die.